2020 Gigabyte Z490 Vision D [10th,8C,K] + RTX 2080 Ti @ 32Gbps-TB3 (AORUS Gaming Box) + Win10 2004 [itsage]
I've had this Z490 desktop for a year now to test on-board Thunderbolt 3. The Vision D motherboards have Titan Ridge controller as well as PCIe 4.0. Due to interest on using Thunderbolt 3 eGPU with mining, I decided to gather up some GPUs to build an amateur mining rig. There's enough space inside for two cards, the third card was attached through a GPU vertical mounting kit. The fourth card is through Thunderbolt connection.
While Thunderbolt 3 eGPU can be plug-and-play on this system, Windows can throw error 12 because there are already 3x dGPUs active. In the BIOS, I set ABOVE 4GB ENCODING to ENABLED and THUNDERBOLT SECURITY settings to NO SECURITY. This helped with handling the Thunderbolt 3 eGPU during system bootup (no hang). Another optimization I did was to switch the LINK SPEED to Gen1. This was due to stability issue in Windows. Prior to this change, Windows would randomly freeze or one of the 3x dGPUs would stop working.
The good news is mining doesn't require much bandwidth at all. Performance is ultimately down to cooling and consistent power. This system runs on a 1000W PSU which handles the 3x dGPUs with ease. As can be seen, the RTX 2070 is an ITX card. It was retracted from the first generation Gaming Box. The coolest graphics card in this setup is the eGPU with its water cooling system.
Here's the screen capture in Nicehash Rig Manager showing the harshrate and other stats.
Keeping a mining rig running 24/7 introduces a few concerns. Heat and noise are the most obvious. I have this in the basement where it's cooler and fan noise is no big deal. Power consumption is is another significant cost on top of equipment. I honestly don't understand why people are paying insane money to buy graphics cards in the past year. Breakeven point is many months if the market cooperates.